As you've got the complete set of data, why don't you simply enter that in JaS' alignment calculator, which you can find in the "Tools" section of VE. That way you can determine the original alignment.

As you can see, Telefunken apparently chose an alignment very close to Baerwald/Loefgren A calclated for an LP playback area according to DIN. So a Baerwald/Loefgren A protractor calculated for DIN radii would get you very close to the original alignment - or you could make yourself a custom two-point protractor with null points at 61.8 and 119.7 mm, if you'd like to exactly replicate the original alignment.

Jean: The calculation above just served the purpose to show, that the original alignment of that Telefunken is very similar to Baerwald/Loefgren A.

For an alignment comparison for that model one would of course need to calculate with the mounting (aka pivot to spindle) distance instead - like this: https://www.vinylengine.com/tonearm_ali ... =calculate As you can see, then the effective lengths would differ accordingly, just as expected.

The offset angle changed. Since the effective length side of the triangle is still the same, the length of the other sides would change due to that small offset angle change.

If effective length is still the same, physically you can't change the others sides : the length of the tonearm can't change, no matter it is J or S shape, unless to break it. And consequently, overhang doesn't change.

If ovehang changed, automatically effective length is changed, this is pure geometry.

And if you change overhang, effective length changes as a geometrical result and also the offset angle changes.

In the diagram, A (effective length) is the same in both. When the offset angle (arrow) changes, the length of B & C change. Consider C as overhang, and you can see how it can change when the offset angle changes, but effective length does not.

How is it possible to increase headshell overhang without increasing effective length ?

In this case, the assumption is that those are two different tonearms, with two different offset angles, but with the same effective length. They would have different construction due to the different offset angles, so different overhang is not a surprise.

The cartridge (unless a direct plug-in mount) has some "wiggle" in the head shell, to tweak offset angle as well as length, by sliding in and out in the slots.

My Rega is set up with a Baerwald, which is slightly different from the "rega" set up (but more accurate/correct) so my cartridge is slightly "twisted" in the headshell, and out as far as it can go in the slots if I remember correctly. Point is: don't sweat a degree or less and a mm or two length difference. Just print your template accurately and align the cartridge to it accurately and enjoy the music!